Petiole in side view trapezoidal; side densely punctate; lacking anteroventral tooth or angle; dorsal face short, wider than long, with convex sides, widest at midlength, faintly microareolate or smooth and shining; posterolateral tubercles low, not at all elevated above posterodorsal margin of tergite, each with a long, stiff seta; postpetiole in dorsal view much wider than long, with slight posterior emargination; anterolateral margins of postpetiolar node dropping abruptly to short, cylindrical neck of helcium; ventral margin of postpetiole with small rounded lobe, lacking sharp anteroventral tooth; dorsum and sides of postpetiole with microareolate sculpture and with 6-8 stiff setae; fourth abdominal tergite with very faint, areolate microsculpture, shiny, with about 50 stiff erect setae evenly dispersed over surface.

A Bolivian collection is generally more robust and more heavily sculptured. The mandibles are striate rather than smooth, the face punctation extends posteriorly along medial border of eye, and the mesosoma is generally more punctate throughout.

Crematogaster abstinensHNS occurs in wet or dry forest habitats, but is more common in the latter. I have never collected this species myself and have no first-hand knowledge of its biology. It has been taking by sweeping on Barro Colorado Island, and by sweeping at night in Brazil (Mato Grosso). Ward collected ground foragers in Bolivia.

Comments

The combination of (1) shiny face, (2) subquadrate dorsal face of petiole, (3) appressed tibial pilosity, (4) very wide postpetiole, and (5) abundant short stiff setae on face that curve toward the median axis uniquely characterize this species. Crematogaster obscurataHNS is somewhat similar but has a punctate face.

I was able to compare directly the types of abstinensHNS, pygmaeaHNS, and suturalisHNS with material that Bill and Emma Mackay collected in Colombia. They were all essentially identical. I examined the types of Wheeler's ornatipilisHNS prior to having additional material for comparison, but my notes and drawings are a close match to the Colombian material, and Wheeler himself considered the species close to abstinensHNS. The Bolivian material that I have for current examination was collected by Phil Ward after my examination of the types of chacoanaHNS and ericiHNS, both from Argentina. My museum notes for chacoanaHNS and ericiHNS describe specimens that were more robust and more heavily punctate than abstinensHNS from northern South America, thus matching the Bolivian specimens. Until more is known of character variation in South America, I am treating the more punctate forms as geographic variants of a broadly defined polytypic abstinensHNS.